Voice Over LTE and IMS

Question 1

LTE Services?

Answer 1

Main service of LTE is data transport

Traditionally voice and message services are provided/controlled by the operator itself

Question 2

LTE Data Transport?

Answer 2

No support for traditional CS domain voice
LTE is designed as a data pipe
Does not care about what application runs over the data

Question 3

Possible Data Applications of LTE?

Answer 3

Web access
Email
Multimedia
Voice
Short Message

Question 4

Delivery of Voice Over LTE?

Answer 4

1. Circuit switched fallback
   - Short term solution
   - Mobile uses legacy 2G or 3G network by moving to a 2G or 3G cell
2. IP Multimedia Subsystem (IMS)
   - Long term solution
   - External network that handles signalling functions needed for voice over IP

Other Approaches

3. Third party providing VoIP service
4. Using dual radios
5. 2/3 G interworking using generic access